T-Mobile will fire up 5G in New York, Los Angeles, Las Vegas and Dallas first, promising to have it up and running in 30 cities total by the end of the year.

So what does this mean for you? Right now… not much. Eventually, 5G will mean waaaaay faster speeds on your various compatible smart devices. How fast, exactly, is still sort of up in the air as telecoms groups nail down and finalize the standards — but it’s fast. Companies have already demonstrated connections upwards of 500 megabytes (not megabits) per second.

The catch: Even if you live in any of the aforementioned cities, you’ll need a 5G-compatible phone to get on that network… and, well, those won’t be available until next year.